A pilot's walk-around, half done

Pull a sample from every sump and hold it to the light. Water sits at the bottom as a clear bead; fuel floats blue above it. The fuel sump is the only place water collects before the engine does.

Pull the control lock pin and move the yoke through its full travel in both axes. A lock left in place has killed experienced pilots on takeoff; the aeroplane simply will not rotate.

The pitot tube feeds the airspeed indicator. With the cover on, or the tube blocked by an insect, the needle lies to you. This is the step people skip because the cover is small and red and looks like it is fine.

Every hinge, every fastener, every control surface moved by hand. You are looking for the one thing that is different from yesterday, which is why the same person should walk the same aircraft the same way each time.